Lifting jack



S. A. SNELL LIFTING JACK Sept. 8, 1936.

3 Sheets-Sheet 1 Filed Oct. 9, 1934 n W R Y O n E .T5 1 N Mm Md n Filed Oct. 9, 1934 3 Sheets-Sheet 2 F154. I F1121 5.

Kill

uuanfr INVENTOR $amue1 A. ne

I 45mm 7 ATTORNEY5 S. A. SNELL Sept. 8, 1936.

LIFTING JACK Filed Oct. 9, 1954 3 Sheets-Sheet 3 INVENTOR Samuel A. Snell Quill/III! v I,"

ATTORNEY Patented Sept. 8, 1936 UNITED: STATES PATENT OFFICE 5 Claims; (Cl.'254-102) This invention-relates in general to lifting. dee vicesgandamoreparticularly tolifting jacks. for use with automotive; vehicles-..

An. object'rofthe present, invention residesin.

the provisionrof :a;- lifting; jaclehaving a single screw cooperatingwithmeans: capable of extendingtthe. effective height of; .the jack; several. times the: enclosed; height :of the jack:v

The invention: embraces. the, provision? of a lifting. jack incorporating-a single screw having telescoping lifting elements cooperating there-.

withewherebyt thaeifective extended height. 01'

the :J'ackisseveral. times the length of the single lifting. screw.

The invention embraces the--provision of .im: provedimeans-forlifting;and supporting the liftingr elements. of the structure;

The invention:- contemplates a jack. of this character; provided: withi. a; plurality of telescop- 20 ing liftingrdeyices. or elements coacting with .-.a

single, screw? and: :having means; for; supportin the. elements;- in:. extended-i position and being;

capable. of; being;automatically" moved. to extendedi position: and: withdrawn: by a simple op- 25 eration of the screw.

A:furthenobject:of; theinvention isto provide a: simp1ified r'jackrof this 7 character wherein the rangement, .operation and function of the related elements ofrthe structure, to various details of constructionyand; togcombinations of parts, element-sper'se, and toqeconomies of. manufacture and-numerous other features as will be apparent frorrra consideration ofthei specification and drawings of certainiiorms of the invention, which.

ybe preferre in. which Figure 1 is a;verti.cal sectional viewxof a lifting 45 jack; forming.- one embodiment 'of the invention;

Figure 2=.;is artransverse sectional. view; taken substantiallyzon: a line. 2=-2 of Figure :1;

Figure-3 isra sectional viewltakerrsubstantially.

OIIJfiEllIlB -3T3.- OfrFi U e 1 Figure.4:is a; vertical; sectional view taken substantially on a line 4- of Figure l;

Figure-5 is anrisometriczviewqof one of the elementsnf the. inventionshowing; a lifting. element:retainingmeansr.

I Figure G is. a,-;front elevation 4 of. the jack with.

portions broken; away to show interior portions thereof;

Figure 7 is an enlarged detailzsectionalview taken. substantially on a .line of. Figure. 6;.

Figure 8:is afragmentary isometric view ofva. portion. of one of the lifting elements showing a form of threaded element associated therewith;

Figure 9 is .a view; similar .toFigurel, withone of the lifting elements in extendedposition;

Figure -'10.is a. sectional .view taken: substani-H tially on a 1ine I-l0 ofFigureQ;

Figure 11 a: detail: sectional view taken sub-- stantially on a line. H-Itl of; Figure 10;

Figure -12:is a;view similarv to Figurerwiththe. lifting; elements; in extended position;

Figure. 13 is'a detail: sectional-viewtaken sub'- stantially one. line l3--l3 of Figure 12;

Figure 14, is a sectional view taken substantially on a line |4--l4 of Figure 9.

The. jack illustrated as embodying-a, formof the inventionis, particularly adapted' for use with. automotive vehicles, but-it .is to be under stood that its use. is'not so limited.

Referring .to; the drawings in detail 'thestructure is shown as inclusiveof a casing or housing I I preferably formed of sheet metal: or other suit-- able material riveted or otherwise secured as 'at' M to abase member l2 .which may alsoibe formed of sheet material. The casingwl l is illustrated as being formed of asingle piece'of sheet metal shaped to. form an enclosure for the working parts. ofv the structure and provided with flange portions l" which maybe riveted or otherwise secured together. as. at I! but it is tov be understood, however, that the-casing maybe of dif'-. ferent constructionvsuch as an; assembly ofztwo 1 or more sections without departing; from, the spirit of the invention The lower portion: of the casing is provided with a laterally projecting; cylindrical, bearing, portion I 9 in the. embodiment illustrated, the bearing portion being, integrally. formed with the casing and arranged tov receive a member, 20, rotatable by means. of ahandle, wrench or other suitable means, for operatingthe. lifting mechanism.

The base 12 supports a member 22 having. arr upturned flange portion 23 of circular configura tion-within which is accommodated a cup-shaped element -or-ball race 25 in which arepositioned a plurality of bearing balls 26. The bearing balls 26- support a circular plate 28 provided with adownwardly extending peripheral flange 29 and' a" series of equally spaced-perforations 3lclrcularly arranged adjacent the, flange 29, form ing a. gear-like structure, A pinion 33' carried by member 20 cooperates with the perforations 3| to impart rotary movement to the plate or gear 28 upon actuation of shaft 25. It is to be understood that a conventional bevel gear may be utilized in lieu of the plate gear herein shown. Plate gear 28 may be of sheet metal of suflicient thickness supporting a threaded element or screw 35 having a non-circular tenon 36 centrally riveted, swaged or otherwise secured to the gear 28 to form a unitary structure, which together with pinion 33 and its shaft 20 form the rotary elements of the device. Screw 35 is preferably provided with square threads 3'! throughout the major portion of its length, a cylindrical reduced portion or neck 38 being provided at the lower end thereof which is entirely free of threads for a purpose to be hereinafter explained.

Interiorly of casing II is provided a member 39, preferably formed of a single sheet of metal member as illustrated in Figure 5, and is formed with a cam portion 5'! and guide portions or channels 58. The portion 51 is provided with a plurality of angularly disposed walls 62 and 84 forming camming surfaces interiorly thereof. The guide 39 is preferably positioned within the casing so that its lower extremity serves to position the gear 28 and prevent upward move ment thereof. The upper end of guide member 39 is positioned with respect to the top of the casing II by means of a flange or collar 54 suitably secured to the casing H. The guide member 39 may be welded as at 43 to the side walls of the casing or otherwise secured thereto in any suitable manner. One of the guide channels 58 is provided with an opening 59 to accommodate an extremity 69 of a leaf or plate spring 5|, the other extremity of which is suitably anchored or secured to the tube 39 by means such as rivet 63.

Within the guide member 39 are provided a plurality of lifting elements or members 49 and 4|, which are preferably constructed to fit or telescope one within the other and adapted for slidable movement with respect to each other and the guide 39. These members are not rotatable, being of non-circular formation in cross section and thus facilitating their manufacture from sheet material by the use of suitable dies. Innermost lifting member 49 is provided with a fiat top surface or seat 42 which may be roughened as at 44 to engage the article or vehicle to be lifted, although such roughening is not essential as there is no tendency for the member 40 to turn on its axis as it is not capable of rotation. The lower end of the member 40 is provided with an internally threaded nut or head 45, preferably positioned and secured thereto by means of projections 46 thereof extending into recesses 4'! which are swaged into depressions in the nut or otherwise secured to the lifting member. As shown in Fig. 11, the nut 45 is formed with a substantially rectangular portion 5| so that the corners or projections 53 extend outwardly beyond the slightly rounded corners of the lifting element or member 49 and serve as a stop means for limiting the upward movement of the lifting element 40 with respect to the outer lifting element 4|. The inner corners of the outer lifting element 4| are provided with projections 52 suitably formed adjacent its upper end to cooperate with the corner projections 53 to carry upward outermost lifting element 4|. The projections are preferably positioned to engage the nut 48 prior to ,the disengagement 0f the nut 5 f m the screw 35 for purposes as will hereinafter apear. p Rotation of the gear 28 in one direction, when the parts are in the position shown in Figure 1, will raise the nut 45 and consequently the lifting member 49. The outermost lifting member 4| is provided with a threaded portion or nut 48 adjacent its lower extremity, the nut 48 being connected thereto by means such as a tongue and groove connection as at 49, the projections 54 of the tube being swaged into depressions formed in the nut as shown at 68 or otherwise fixedly secured together. Nut 48 is preferably provided with projections 59 serving as stop members extending beyond the sides of member 4|, and is also provided with internal screw threads 54 adapted to cooperate with threads 31 on screw 35. The outer lifting member 4| and its cooperating threaded nut or head portion 48 are held in ineffective position during an upward range of movement of the inner lifting member 40 or until portion 5| engages the stop means provided adjacent the upper portion of the outer lifting element 4|. Extremity 60 of the spring BI is preferably formed so that a portion extends inwardly through the opening 59 in guide 39 to engage nut 45 and serve as a resilient stop means to hold the outer lifting element 4| in its lowermost position until the inner lifting element 40 has traveled through its independent range of movement upon rotation of the screw 35.

Forming a portion of the element 4| is a channel-shaped member 65 which is urged normally outwardly by means of the spring 61 while the outer lifting element 4| is in its lowermost position. The lower end of the channel member 65 engages the nut 48 and as this nut is moved upwardly into engagement with screw 35, the nut in turn elevates the channel member 65 in a manner hereinafter described. The channel member 65 forms a support between the lowermost portion of the inner lifting element and the nut 48 to provide a means for supporting inner lifting element as the outer lifting element is elevated.

The spring 61, preferably secured to the channel member by means such as rivet 69, applies tension between the lifting elements 40 and 4| which tends to prevent movement of the outer member 4| upon upward movement of element 49. When the lifting element 40 is in the position indicated in Figure 9, the tension of spring 6? is decreased, being then in engagement with screw 35. As the nut 48 and element 4| move upwardly, the channel member 65 is moved inwardly toward the screw 35 by the angular or cam surfaces 62 and 64, the upper extremity of member 65 contacting the cam surface 64 and an angular projection 78 at the lower extremity of the member 65 engaging the cam 62, thus maintaining the member 65 substantially in a vertical position. Spring 5'! holds the projection 79 in engagement with the inner surface of cam 51 during movement of element 4| and support 65 until they reach their approximate uppermost position as shown in Figure 12, at which time the tension of spring 61 is released. During downward movement of the elements 40 and 4|, the spring 61 insures outward movement of channel 65 to permit the complete withdrawal of element 40 into the member 4|.

As clearly illustrated in Figures 6 and '7, an alternative means is disclosed for resiliently looking the outer member in its lowermost position. Opening 12 through casing or housing H and Cal element M eiijaeent its lower extremity. As

openings :ta and t2 Goinci'de', the' ball '14 'isforc'ed into the naming it by t'he ten'sion of spring 1 5,

normally resisting upward movement of the lifting element t I o -'opeiate the parts from retractedposition,-as i-llustrateii in Figures 1 and 4, a suitable tool or operating handle 68 is inserted in an opening contained in the shaft 20 and the same rotated to cause rotation of gear 33 which, meshing with the plate gear 28, causes rotation of the screw 35. As the nut 45 fixed to the lifting member 40 is in mesh with the threads 31 of the vertical screw 35, the member will be elevated during rotation of the gears. When the member 4! has been extended substantially to the position indicated in Figure 9 or until the corners of the nut 45 engage with the stops 53 in the corners of the lifting member 4|, continued ro tation of the operating gears will initiate upward movement of the outer lifting member 4| by moving the threads of the nut 48 into engagement with the threads 31 on the vertical screw 35. Both of the lifting members 45 and 4| move upwardly in fixed relation as the member 65 is in engagement or in contact with the walls of the cam portion 51 in the guide member 39, which cam surface causes an inward movement on the supporting member 55. Thus, the member 65 is moved beneath the inner lifting member 40, to form a rigid and strong support therefor after the nut 45 has been moved out of the mesh with the threads 31 of the vertical screw. Further rotation of the screw will extend the lifting elements 49 and 4| to substantially the position shown in Figure 12 or until the projections 55 of nut 48 are in engagement with the upper end of the end of guide channel 58.

Rotation of the gears and the vertical screw in the opposite direction will retract the lifting members until the threads of the nut 45 again mesh with the threads of the screw 35 and, for a short period of rotation of the screw, both nuts 45 and 48 are in mesh with the threads on the vertical screw. At approximately this time, the member 65 has reached a position with respect to the guide 51 which permits it to be moved outwardly by means of the spring 61 away from position beneath the inner lifting element so as to permit the latter to be further retracted. The nut 48 in the outer lifting element 4| reaches its lowermost position as indicated in Figure 9, being out of threaded engagement with the threads of the screw, which is the lowermost position of the outer lifting element. Further rotation of the screw will retract the inner lifting element substantially to its initial or completely retracted position.

It has been found desirable to construct a lifting jack of this character so that the frictional coefficient between the outer lifting element and its guide member is greater than the coefficient of friction between the contacting surfaces of the inner and outer lifting elements. This has been accomplished by providing the tension spring between the inner and outer lifting elements in their lowermost position to maintain friction between the outer lifting element and the screw and a partial release of friction component when the lifting elements are in the uppermost posi-tien. By means of such an arran'ge- 'r'nent ,-"shoul'd the jack-be used-ih a position that alateral strain isimposedupon the'lifting elements, friction between outer and inner lif-ting elements will tend to prevent the outer lifting elemeri'flfrom being carried upwardly during upward m'ovement of the 1 inner member prior "to the eng agement of -'corne'rs of '-'the nut with the projections in the outer liftingelement, thereby pro- 'viding a satisfactory and smoothly operating inechanis'm.

lt is apparent thatgwi-thin the-scope of themvention modifications and different arrangements may be made other than are herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

What I claim is:

1. A lifting jack including a casing; a gear in said casing; a plurality of lifting elements in said casing; a rotatable screw; means associated with said' lifting elements and cooperating with said screw for successively elevating and retracting said lifting elements; means for supporting one of said lifting elements when in elevated position including a laterally movable member; means normally urging said member to ineffective position; means to move said member laterally into position to support one of said lifting elements; and resilient means cooperating with one of said lifting elements to retain same within the casing during elevation of another of said lifting elements.

2. A lifting jack including a casing; a gear in said casing; a plurality of lifting elements in said casing; a rotatable screw; means associated with said lifting elements and cooperating with said screw for successively elevating and retracting said lifting elements; means for supporting one of said lifting elements when in elevated position including a laterally movable member; spring means normally urging said member to ineffective position; means including a cam to move said member laterally into position to support one of said lifting elements; and spring means engageable with one of said lifting elements to retain same within the casing during elevation of another of said lifting elements.

3. A lifting jack including a casing; a gear in said casing; a plurality of lifting elements in said casing; a rotatable screw; means associated with said lifting elements and cooperating with said screw for successively elevating and retracting said lifting elements; means for supporting one of said lifting elements when in elevated position including a laterally movable member; spring means normally urging said member to ineffective position; means including a cam to move said member laterally into position to support one of said lifting elements; one of said lifting elements having a recess; and resilient means relatively fixed with respect to said housing and adapted for cooperation with said recess for retaining one of said lifting elements within the casing during elevation of another of said elements.

4. A lifting jack including a casing; a sleeve fixed within said casing; a gear in said casing; a plurality of lifting elements in said casing; rotatable screw means associated with said lifting elements for successively elevating and retracting said lifting elements; means for supporting one of said lifting elements when in elevated position including a laterally movable member; spring means normally urging said member to ineffective position; means including a cam to move said member laterally into position to support one of said lifting elements; one of said lifting elements having a recess; and resilient means cooperating with said sleeve and the recess in said lifting element for retaining the latter within the casing during elevation of another of said lifting elements.

5. A lifting jack including a casing; a gear in said casing; a plurality of lifting elements in said casing; a rotatable screw; means associated with said lifting elements and cooperating with said screw for successively elevating and retracting said lifting elements; means for supporting one of said lifting elements when in elevated position including a laterally movable member; spring means normally urging said member to ineffective position; means including a cam to move said member laterally into position to support one of said lifting elements; an opening in a wall of the casing; one of said lifting elements having a recess; a ball contained within the opening in said casing wall; spring means urging said ball into the recess in said lifting element whereby said lifting element is retained within said casing dur- 10 ing elevation of another of said lifting elements. SAMUEL A. SNELL. 

